Add missing smov support, and clean up existing umov support.

Add missing smov support, and clean up existing umov support.

	sim/aarch64/
	* simulator.c (do_vec_SMOV_into_scalar): New.
	(do_vec_UMOV_into_scalar): Renamed from do_vec_MOV_into_scalar.
	Rewritten.
	(do_vec_UMOV): Merged into do_vec_UMOV_into_scalar and deleted.
	(do_vec_op1): Move do_vec_TRN call and do_vec_UZP call.  Add
	do_vec_SMOV_into_scalar call.  Delete do_vec_MOV_into_scalar and
	do_vec_UMOV calls.  Add do_vec_UMOV_into_scalar call.

	sim/testsuite/sim/aarch64/
	* sumov.s: New.